Many states do this now. It's virtually impossible to live in this day and age without an official state issued ID card -- either a driver's license or state ID card. (Some states issue an official ID card for those who don't have a license). Other IDs like credit cards or employer work-IDs are no longer accepted.
This includes even when you are paying cash up front for something -- they still want ID to see that you are who you claim you are.
I'm a little troubled by this. Why can't someone have some anonymity in their life? If I go to a doctor and pay the $75 in cash up front, why do they need to see ID? Even when you rent a storage locker and pay in advance they want ID.
This country has to come to terms with its CONTRADICTORY policies of illegal immigrants. On the one hand, they expend a great deal of effort keeping illegals out. But once they're here, they're afforded lots of benefits and rarely get kicked out, and that's not fair to those waiting through proper channels for a quota slot.
Illegal aliens cost some places big money since they have to provide services but the illegals tend to be "underground" and not pay any taxes nor are counted for reimbursement. On the other hand, illegals fill employment needs for jobs more established Americans refuse to take.
A lot of business interests very much illegals to be left alone.
The driver's license is pretty much already a national ID. However, I don't agree with the above. Terrorists are not isolated and are bankrolled; as such, they can spend the money needed to beat the system. Further, the existing system has and will continue to have more holes than a screen door -- making these ID cards won't help. As to "moving about freely", will the govt establish official checkpoints at various places? "Your papers? No papers? You will have to come with us?"
How many terrorists have entered this country? Counting all those methods described above, it appears to be a very great many.